Vacuum formed PEI Custom Part as a Print Surface

So out of curiosity, I called up a company that professionally makes PEI parts (mostly for medical application). My idea was that you could wrap PEI around a print bed and manufacture it as a single piece and perhaps get a nice, ready to print on surface (ideally flat aluminum wrapped in PEI).

This wasn't something that they typically did - but they could make a custom shaped PEI part by vacuum forming.

From what I understand, they CNC or create a mold and then vacuum form the PEI to the shape of the mold - so I got a price quoted for a 310mm diameter plate like the Rostock Printer uses. Apparently the molds are porous to allow air to pass through, so the inside (?) of the PEI shape is cloudy in texture.

It's quite expensive for even a prototype run of parts, but once the molds are created, then the parts and labor cost is lower.

Via their replies:

As we discussed we could potentially form the part but this would require at least a $7.5K, if not more development investment. Parts would then probably be at least $20 each just based on material cost alone. We have 3mil, 5mil, 7mil, 15mil, 20mil PEI available.

It's probably not something I'm going to pursue further - but it was an interesting thought to have a PEI "shell" that you could fit a glass round into and clip to your printer bed. It should keep it shape well if clipped to another flat object, but I'm not sure a vacuum formed PEI part has advantages over a simple sheet (unless perhaps the sheets tend to warp more than the vacuum forming).

Anyway, I'm not willing to bet $7.5k upfront that a vacuum formed PEI print surface would be better than standard PEI + adhesive, but I thought I'd leave this post here for anyone else who was curious.

There is a german company that makes the sort of thing you mention basically a toolplate bed with PEI surface coating (it is thought that they probably disolve PEI Granules in a solvent and then spray it onto the surface apparently this solvent is not nice to work with).